Growing hard lump under the right buttock, feels sore. Cerical cancer in family. Any relation ?

Hi Dr, i have found a lump under my right bum cheek its really hard and i have felt sore for weeks but the lump has slightly grown, it hurst when i walk or sit down and i have to sit leaning, my mum has just been diagnoised with cervical cancer and im terrified, please do you have any advice, i have an appointment with my GP today but im worried as he is a male and its embarassing.